Marco Rubio. Mark Wilson/Getty Images Marco Rubio's presidential campaign said Friday that it was embracing the unusual political tactic of telling some voters not to vote for him.

Rubio, a senator from Florida, is trying to halt GOP frontrunner Donald Trump's momentum by denying him two big wins on Tuesday.

Both Rubio and his opponent Gov. John Kasich of Ohio are trying to win their home states, which are among the two biggest contests to award their delegates on a winner-take-all basis.

Rubio's communications director, Alex Conant, argued Friday on CNN that the logic was "indisputable" for anti-Trump voters in Ohio and Florida:

I'm just stating the obvious. If you are a Republican primary voter in Ohio and you want to defeat Donald Trump, your best chance in Ohio is John Kasich. Because John Kasich is the sitting governor. He's very close to Donald Trump in some of the polls there.

The same is true here in Florida — where if you want to defeat Donald Trump here in Florida, where there's 99 delegates at stake — you need to vote for Marco Rubio. Because he's the only one with a mathematical shot, and if you look at the polls and the early voting, a very good shot at beating Donald Trump here.

Rubio's calculation echoed that of 2012 GOP nominee Mitt Romney, who last week similarly urged strategic voting for anti-Trump voters across the various states.

It's not necessarily a huge sacrifice for the Rubio campaign to abandon Ohio, where one recent poll found the candidate with just 5% support. Conant's interview is nevertheless a remarkable sign of how dominant Trump has become in the GOP primary.

The Kasich campaign reportedly suggested in response that it wouldn't reciprocate the Rubio campaign's strategy. At least one poll has shown Kasich leading Trump in the Buckeye State, while an average of recent Florida polls has put Rubio behind Trump by double digits in the state.

If Trump wins both Ohio and Florida next week, number crunchers have widely predicted that the frontrunner's delegate lead will become almost impossible to overcome unless his campaign were to implode.